The present invention is directed generally to plate lifting clamps for lifting a plate and, more particularly, to a plate lifting clamp with a pawl that locks the device to maintain a clamping force on the plate.
A plate lifting clamp includes a gap to receive an edge of a plate. The gap is formed between a fixed edge and a movable edge. This construction provides for a width of the gap to be adjusted to accommodate plates of varying thicknesses, and also to maintain a clamping force on the plate. A securing mechanism is operatively attached to the movable edge to maintain the clamping force on the plate. In use, the plate lifting clamp is attached to an edge of the plate. Once attached, the plate lifting clamp is attached to a lifting device that lifts both the clamp and the plate. The securing mechanism maintains the movable edge against the plate while the plate is being lifted to prevent inadvertent disengagement of the plate.
Various prior designs have included a lever-actuated mechanism to maintain the movable edge against the plate. These designs were constructed and positioned to engage the movable edge and prevent movement away from the fixed edge. However, these designs may become jammed thus preventing the movable edge from being moved away from the fixed edge. This jamming results in the plate lifting clamp remaining attached to the plate. In addition, many prior designs are cumbersome, particularly those designs that include pieces that are detached from the plate lifting clamp. Further, many of prior designs are not intuitive for the users to determine how to use them As such, there remains a need for alternative plate lifting clamp designs.